Electrical connector with insulation piercing means contacting the conductors of electric cords



G B. BENANDER TAL 2,655,639

ELECTRICAL CONNECTOR WITH INSULA ION PIERCING MEANS Oct. 13, 1953 CONTACTING THE CONDUCTORS OF ELECTRIC CORDS Filed Dec. 29, 1951 Ffgl. P-

4 WII Inventors:

George B. Benancler,

G ustaf R. Lawson Patented Oct. 13, 1953 ELECTRICAL. CONNECTOR WITH. INSULA- TION PIERCING MEANS CONTAGTING THE CONDUCTORS F ELECTRIC CORDS George B.. Benander, Oaklawn, R. I., and Gustaf B.. Lawson, Abington, Mass, assignors to Gen.- eral Electric Company, a corporation of New York Appli'oaationnecember 29, 1951', SerialN'o. 264,068

1 Claim. 1

This invention relates to end attachments for electric cords and, in particular, to a flat electric tap and the mechanism'ior connecting the same to an electric cord".

By flat tap is meant that type of electrical device which may be connected to the end of an electrical cord to provide one or more receptacles for receiving the blades: of attachment caps or male connector plugs for supplying power to lamps and other electrical appliances.

This invention has for a primary object the provision of an improved flat tap which can be connected to an electric cord without the use. of tools or mechanical skill.

, It. is a still further object of this invention to provide an improved flat tap which may be easily connected to an electric cord of various sizes and which has good strain relief properties.

Further objects and advantages of this invention will become apparent and the invention will be more clearly understood from the following description referring to the accompanying drawing, and the features of novelty which characterize this invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

Briefly, this invention comprises the combination of a housing, electric terminals, strip elements which are positioned to form a plurality of connectors for an electric flat tap, and an impaling cam for connecting the terminals to an electric cord.

While we do not intend to limit this invention to a tap having any particular number of pairs of openings, a triple tap has been chosen for the purpose of this description to illustrate more clearly the operating features of this invention.

In the drawing, Fig. 1 is a top elevation of a flat tap; Fig. 2 is a bottom elevation, partially cut away, of the fiat tap; Fig. 3 is a side elevation taken along the plane 3-3 of Fig. 1 in the direction of the arrows; Fig. 4 is a second sectional view taken through the plane 33 of Fig. 1 in the direction of the arrows showing an electric cord inserted into the housing; while Fig. 5 is an end view taken through the plane 5--5 of Fig. 4 in the direction of the arrows.

In the drawing, the flat tap I is shown comprising a housing 2 having an upper portion 3 and a base or lower portion 4. The upper portion 3 has a plurality of pairs of openings 5 through which the contact blades of a plug connector may be inserted into the tap and the base 4 supports an impaling cam 6 and screws 1 for holding the upper portion 3 and base 4 in assembled relationship,

(Cl. 33999)v Housing 2 can be made of any of the phenolic or urea resins or any other insulating material which. issuitable to Underwriters Laboratories, Inc.

The upper portion 3- of the housing has in one end wall a cord inlet: passageway 8, and walls which define a prong or impaling cavity 9, and a gripping passageway ID with which passageway 8 connects. The dimensions of each of these passageways are such that a twin conductor cord can be pushed axially through the passageway 8 through prong cavity S-into the gripping passageway IO.

In gripping passageway I0, a wall H of insulating material is positioned to lie between the ends of the twin conductor cord to insulate them from one another;

The upper housingportion 3 also has a pair of cavities I2 lying beneath opening 5 to position a pair of terminal strips l3 which support, preferably as an integral part thereof, prongs [4 to which electric cord conductors may be connected and resilient portions [5 for engaging the blades of plug connectors (not shown) inserted through openings 5.

The base 4 of housing 2 has an aperture or slot [6, the peripheral boundaries of which support impaling cam 6. The cam, in turn, has an axial bore I l for receiving a bearing pin [8 which is nested in a pair of grooves 19 located one on either side of the slot l6.

With this structure, the impaling cam 6 can be rotated to the wire admitting position shown in giig. 2 or to the wire gripping position shown in Pin 18 is made of flexible steel or other resilient material so that it will deflect and thereby vary the actual position of cam 6 to compensate for wire diameters, thus adapting the tap for connection to electric cords of diiferent sizes.

Base 4 further furnishes a nesting shoulder 2a which is adapted to position an insulating strip 2| so that it will lie between an electrical cord 22 (Fig. 4) and the impaling cam 6. The purpose of the insulating strip is to reduce the friction between the impaling cam 6 and the outer surfaces of the electric cord 22.

When upper portion 3 and base 4 are assembled to form a completed housing 2, screws 1 are passed through suitable bores in the base to engage threaded holes in upper portion 3 thereby holding the parts in assembled relation.

When'the housing has been so assembled, electrical cord 22 may be passed through cord passageway 8 into prong cavity 9 and into the gripping passageway lfl whereupon the ends of each conductor of the cord are insulated from one another by passing one on either side of wall I I.

After being fully inserted into the housing, cord 22 will be juxtaposed but not in electrical contact with the prongs l4, and it is only after impaling cam 6 is rotated towards the position shown in Fig. 4 that the conductors of cord 22 are pierced by the prongs H. In the rotation of the cam to its impaling position, the insulating strip 2| is pressed by the cam 6 toward the upper housing portion 3 to squeeze and thus grip cord 22 in the gripping passage Hi.

This structure furnishes a good electrical connection between the prongs and the cord H, and it also provides a mechanical connection in the gripping passageway l0, thus assuring good strain relief action for holding cord 22 in tap I. This strain relief action is enhanced by the kinks put in cord 22 by the impaling cam after it has been rotated to the position shown in Fig. 4.

Modifications of this invention will occur to those skilled in the art, and it is desired to be understood, therefore, that this invention is not intended to be limited to the particular embodiment disclosed but rather is it intended to cover all modifications which are within the true scope of this invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

A flat tap comprising an upper housing portion having top, side and end walls and an open bottom, said top wall having pairs of openings to receive the blades of an attachment cap and one of said end walls having an open-ended notch which forms a cord inlet passageway, walls projecting from the inner face of the top wall which define two grooves, one on each side or the upper housing portion, which extend longitudinally of such housing portion from one end wall to the other, and a prong cavity and a gripping passageway with which said end wall notch connects, a strip contact in each groove having resilient contact portions which are in alignment with said pairs of openings and prongs having pointed ends positioned in said prong cavity, a flat base fastened over the open bottom of said upper portion which closes said notch and has a longitudinally extending opening in line with said prong cavity, a pivot pin held between the flat base and the upper hOusing portion which extends across said longitudinally extending opening, an impaling cam pivotally mounted in said opening on the pin, a wall forming a shoulder on the base which is located in the outer end of said notch for locating the base on the upper housing portion and cooperating with the notch to form a conductor inlet opening, and a flexible insulating strip which extends longitudinally across said prong cavity beneath said cam and at one end abuts against said shoulder.

GEORGE B. BENANDER. GUSTAF R. LAWSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,960,191 Staub May 22, 1934 2,025,214 Moulthrop Dec. 24, 1935 2,162,545 Benander June 13, 1939 2,482,966 Cook Sept. 27, 1949 2,590,886 Pedersen Apr. 1, 1952 

